In many forging processes, a billet or other form of raw material is heated prior to being plastically deformed in a press. After the deformation step, the finished part is cooled by being placed in a quench tank. The rate of cooling provided by the quench tank helps determine the structural properties of the finished product. Often, due to an interruption of production of the forging press or problem reaching desired temperatures in a preheat furnace, billets that have been heated cannot be used in the press. However, due to the risks involved with movement and storage of hot billets, these billets are sent directly to a second quench tank, so they can be cooled, stored and reused at another time.
In the most common version of either type of quench tank, fresh water is input on one side of the tank, and as this causes the water level in the quench tank to rise, an overflow drain is used to remove excess cooling water. Fresh water provides a good medium for cooling and also for removing impurities or scale from the surface of a finished part. As the cooling water flows into the drain, these impurities are taken away. Water leaving the quench tank through the drain may be treated or otherwise moved off site. Depending on the cost of water supply and disposal, quench water may be treated and reused, however, treatment costs may be high.
What is desired is an improved quenching process for use in association with forging or other industrial operations.